PSMB9 and esophageal squamous cell carcinoma: We found a clear increased risk of ESCC in the Kazakh population for the heterozygous LMP2 R/C genotype and the homozygous C/C genotype (OR = 1.470, 95%CI = 1.076–2.008, p = 0.015 forLMP2R/C; OR = 2.048, 95% CI = 1.168–3.591, p = 0.011 for LMP2 C/C).